Ultrasonic imaging has rapidly become a preferred modality for the non-invasive investigation of human tissues. Its non-ionizing character, moderate requirements in terms of signal processing and computation support, compactness, and, continuing progress in image quality, all mandate in favor of ultrasound whenever conditions permit. Thus, with the exception of body areas which are subject to uncontrolled multiple reflections (e.g. in the skull) and areas which fundamentally possess poor sonic transmission characteristics (e.g. the lungs), most body parts have been successfully made the subject of ultrasound diagnosis or screening. Some systems are multipurpose in essence, such as real time or B-scan body scanners and fetal monitors, while others are highly specialized, such as pulsed Doppler carotid imagers and flow monitors.
Recently, scientific and clinical data have been produced which provide strong indication of the efficacy of ultrasound scanning and imaging to screen, detect, and diagnose lesions in the human breast. In particular, it appears that appropriately directed and controlled B-scan images of a human breast permit detection of lesions in the 1 to 2 millimeter range and discrimination of malignancies in the 5 millimeter range based solely on ultrasound image. Further such screening appears feasible at statistical levels of confidence comparable to those achieved through utilization of ionizing radiation (i.e. X-ray mammography). Such efficacy, together with ultrasound's apparent hazard free nature, makes ultrasound a likely preferred modality for large scale screening programs for early detection of breast cancer.
It is accordingly a primary object of the present invention to provide apparatus employing the principles of ultrasound pulse-echo imaging for the screening of the breast, and further to provide control mechanisms and image quality which permit diagnostic utilization in accordance with the level of skill in the art.
It is another object to provide such apparatus which is readily and efficiently adjustable to accommodate substantially all women, irrespective of body physique or breast size or shape.
It is yet a further object that machine adjustment be quickly and conveniently achieved whereby large numbers of women may be quickly and effectively scanned, thereby to minimize the per procedure cost, and to promote effective large scale screening programs.